1. Field of the invention
The present invention relates to an electronic control unit and a method for compensating for a torque steer.
2. Description of the Prior Art
In general, the phenomenon in which the body shell of a vehicle is tilted to one side as a result of a difference between the driving forces of the left and right wheels when the vehicle abruptly starts is called a torque steer phenomenon.
The causes of the torque steer include the difference between the lengths of the left and right drive shafts and the difference between the bending angles of the left and right drive shafts.
The method of solving the torque steer includes a method of adding an intermediate shaft to a short drive shaft in order to make the lengths of the drive shafts and bending angles the same and also includes a method of compensating for a torque steer by using a power steering system.
Among them, the conventional method of compensating for a torque steer using a power steering system is to estimate the degree of the torque steer by using an engine RPM, an engine torque, an acceleration pedal manipulation degree, and the speed of the vehicle by an electronic control unit (ECU) of a power steering system and to apply a compensation current to an electric motor that is proportional to the estimated torque steer.
In the above-mentioned conventional method, a torque steer degree is estimated by using indirect information on a torque steer, such as an engine RPM, an engine torque, an acceleration pedal manipulation degree, and the speed of the vehicle, and because direct information on a torque steer, such as the slip degrees of the left and right wheels of the vehicle is not used, a torque steer degree that may vary according to a change in the slip degrees of the wheels of the vehicle cannot be precisely recognized.
Accordingly, if a torque steer is compensated for in an electronic control unit of a power steering system according to the conventional method, the torque steer that occurs cannot actually be appropriately reduced.